Tech Talk – April 2018

Thin gauged porcelain tile – North American research, collaboration, and standardization

By Bill Griese, Director of Standards Development, Tile Council of North America and Noah Chitty, Director of Technical Services, Crossville Inc.

In February, TCNA’s Bill Griese and Crossville’s Noah Chitty traveled to Castellón, Spain, to lecture to the Congress of Qualicer 2018 on research and standardization of thin gauged porcelain tiles and tile panels (GPTP) in North America. Following are highlights of their white paper on this subject, which was presented at Qualicer 2018. The paper, in its entirety with works cited, is available online at tileletter.com.

ANSI A 137.3 and ANSI A108.19

 

In 2017, the North American tile industry released two new standards: ANSI A137.3, American National Standard Specifications for Gauged Porcelain Tiles and Gauged Porcelain Tile Panels/Slabs, and its companion, ANSI A108.19, Interior Installation of Gauged Porcelain Tiles and Gauged Porcelain Tile Panels/Slabs by the Thin-Bed Method bonded with Modified Dry-Set Cement Mortar or Improved Modified Dry-Set Cement Mortar. These standards, developed for the benefit of all tile consumers, are the result of a multi-year research and consensus process of the ANSI Accredited A108 Standards Committee, which includes participants from all industry sectors. 

These efforts aimed to establish a framework for specifications of products that are intentionally “gauged” to a specific thickness. Currently two classes of gauged tile products are defined by the standards: 

Those for wall applications from 3.5mm to 4.9mm and 

Those for floor and wall applications, from 5.0mm to 6.5mm. 

Other products, which either fall outside of these ranges or for which the manufacturer has not specifically provided a gauged-thickness designation, continue to be standardized under traditional tile specifications.

Terminology and strength criteria

One of the earliest topics on which the North American industry debated was terminology. These products were called “thin” tile, but since the same technologies are also used to create thick tiles – and end-users had increasingly prioritized tile thickness as a key characteristic – a new moniker was needed. Hence, the term “gauged” was born, basing the term on one used for other construction products – such as electrical wire and sheet metal – which carry different load capabilities and usage parameters across a variety of gauges. The group agreed to further differentiate gauged products based on their size, with gauged tiles being less than a square meter and gauged tile panels/slabs being greater than or equal to one square meter. 

In developing product performance criteria, the first key concern was breaking strength, as the North American requirement for traditional tiles was 250 lbf. Initially, very few – if any – thin gauged products met the requirement. Therefore, installed strength became the key to achieving performance levels comparable to those of traditional tiles whose exceedingly high breaking strength could often make up for flaws in mortar coverage or quality. With thin gauged tiles, though, the group chose to scrutinize how lower breaking strength may be offset by installation rigidity and increased mortar coverage.

Key provisions of the installation standard

To develop ANSI A108.19 Interior Installation of Gauged Porcelain Tiles and Gauged Porcelain Tile Panels/Slabs by the Thin-Bed Method bonded with Modified Dry-Set Cement Mortar or Improved Modified Dry-Set Cement Mortar, a group of installers, architects, and manufacturers conducted countless experiments to discover application and embedding techniques that make possible maximum mortar coverage, particularly for tile panels/slabs. Through these experiments, standard setting procedures for gauged porcelain tiles and tile panels/slabs were developed that facilitate optimal workmanship and system integrity. 

Mortar application: It was determined that applying a layer of mortar to both the back of the panel/slab and the substrate would result in the necessary bond coat thickness of 3/16” (4.8mm) and would allow for full encapsulation of lippage control systems. Anything less than this method would result in an embedded mortar layer thickness that was insufficient to achieve the agreed-upon substrate tolerance of a maximum deviation of 1/8” in 10 horizontal feet (3mm in 3m) from the required plane when measured from the high points in the surface for floors.

Mortar properties: Mortar properties such as extended open time, flow to achieve coverage, and curing parameters appropriate to the application, as well as a requirement for suitable mortar identification through consultation with the tile and setting material manufacturer are specified in the standard. 

Trowels: Only Euro-trowel, Flow-Ridge trowel, and Superior notch trowel can facilitate ridge collapse without the need to press and slide the tile. The group agreed to standardize the use of such trowels.

Embedding procedures: For floors, physically walking on the surface in the following pattern produces the greatest supporting mortar coverage: 

1) walk down the centerline of the tile; 

2) take small shuffling steps left and right from center to push air toward the edges.

This standardized procedure is listed in ANSI A108.19 for embedding tile panels/slabs on floors. For walls, a vibration tool and weighted beat-in paddle are specified in order to achieve optimal coverage.

For walls and floors, a vibrational tool used at the perimeter, achieved full coverage on the edge, critical for overall durability in flooring applications, and also facilitated full encapsulation of lippage control systems. For these reasons, edge coverage achieved through vibration is a provision of ANSI A108.19. The standard minimum required coverage is 80% for walls and 85% for floors. Additionally, maximum void size was established as 2 square inches (1290 square mm).

Coverage calculation: A standardized evaluation to calculate coverage was developed. ANSI A108.19 states, “In any single square foot under the embedded tile, coverage… is calculated by measuring the voids and the marked off square foot and dividing by 144 square inches (929 square cm) where the dry set mortar is not in full contact from the back of the tile to the substrate.”

Substrates: Standardized suitable substrates for the installation of gauged porcelain tiles and tile panels/slabs are mostly consistent with those of traditional tile, with the exception of direct bonding to plywood floors, which requires the use of a mortar bed or specified backer board and referencing floor rigidity requirements established by building codes and other widespread industry specifications. 

Applicable to all substrates, ANSI A108.19 details required flatness as maximum deviation of 1/8” over 10’ (3mm in 3m) from the required plane when measured from the high points in the surface.

Material handling: Qualified labor and other provisions also taken into account through discussion and A108.19 standardization were adequate jobsite storage, space to maneuver panels, prevention of damage while handling and time for mortar curing. Another critical aspect of ANSI A108.19 involves usage of properly qualified installers who are equipped with proper tools and have acquired sufficient product knowledge and installation experience. 

There are several other key provisions contained within ANSI A108.19, including grouting, workmanship, movement accommodation, and maintenance, completing a very comprehensive specification for how to install products defined by ANSI A137.3. 

See link here for the full paper, including footnotes. 

57_PON_ING

Tech Talk – March 2018

How to Get Paid for Floor Prep Work

By Tom D. Lynch, CSI

I bet you’re thinking, “This ought to be good. What does this guy know that I haven’t already tried? Getting architects and owners to agree to pay for floor-prep work is about as easy as it is to get a concrete contractor to provide a perfectly flat and level floor in the first place.” And the answer to this question could very well be “You just read it.” He who pours the concrete that does not meet the specs should fix the floor so that it does meet the specs or pay someone else – like you – to fix it for him. Sound simple? It’s not.

Part one: the problem 

The problem is getting the concrete guy to meet whose specs; his Division 3 specs or our Division 9 specs? The Division 9 specs most times spell out precise finish floor requirements as if it were the tile installer’s responsibility even though he did not pour the concrete. The Division 3 specs in general do not get specific when it comes to finish floor requirements. The Tile Council of North America (TCNA) gives very definite requirements for substrate tolerances but does not spell out whose responsibility it is to provide them. We therefore have a dilemma.

A couple years ago the American Society of Concrete Contractors (ASCC) in conjunction with the Flooring Contractors Association (FCCA) and the National Wood Flooring Association (NWFA) issued a joint statement titled the “ASCC Position Statement #6” to address this issue. Without going into great detail about the differences between the two specs, the conclusion of the ASCC and the NWFA was as follows:

“….suggest that the owner provide a bid allowance, established by the A/E and based on the floor covering requirements, for any necessary grinding and patching to close the gap between Division 3 tolerances and Division 9 tolerances.”

This sounded good to everyone except the owners who unfortunately have to foot the bill. Where is the control over quality with this plan? There is none, and that is the flaw with this position. Issuing blank checks in the construction industry just doesn’t work.

There is more to this issue than meets the eye, and must be considered. The floor covering industry is changing, and changing fast. With the ever-increasing demand for large-bodied tiles plus the advent of gauged porcelain slabs and panels, the demands for flat and level floors has increased dramatically. Add to this the ever-growing demand for luxury vinyl tiles (LVT) that also demand extremely flat and level floors, and it is plain to see that nearly every type of floor covering other than carpet requires a minimum of 1/8” in 10’ flatness levels.

Case in point

Progress is not being made along these fronts and it is not fair to anyone involved. Let me give you an example: In the spring of last year I received a frantic phone call from a good tile contractor friend of mine in Houston, Texas. He had a large ceramic and resilient tile project in progress for one of the largest building contractors in the country and was up against the wall with a substrate issue that was going nowhere toward resolution. The concrete floors were so bad that his “more than fair” estimate to repair them came to well over $100,000 and no one would listen to him. For some reason, the owner of the project was protecting the concrete contractor and would not consider paying out any money to resolve the issue.

After a day of taking laser readings and laying out a complete diagram of the floor variations we were able to convince the GC that the floors were in fact, that bad. It was obviously not my friend’s fault, but the owner still would not relent. So, I advised my client to offer to sell all the tile materials that were already on site to the owner and let him find someone else to perform the install. My reasoning was that my client – as a professional flooring contractor – could not in good conscience knowingly perform an inferior installation. Unless he was allowed to repair the floors and get paid to do it, he was willing to walk. The GC, by the way, respected him greatly for taking the position that he did, and the owner finally relented.

The moral of the story is to stand by what you know is correct and proper. A tile contractor should never be forced to give in and fix someone else’s concrete work for free. A solution must be made.

Part two: the solution

This is not simply a concrete slab issue nor only a ceramic tile issue, but rather an issue involving both trades that must be worked out together in such a manner as to be acceptable to architects and fair to owners. I propose a new specification section: 09300.5 Concrete Floor Prep. The Division 3 specification will also need some revisions made to it. The system would be as follows:

The concrete slab shall be poured 1/2” below the desired finish floor height. No fine finished trowel surface will be required. Basically a bull float and broom finish is all that is needed. This will save money in two ways. First, 1/2” less material will be used and secondly there will be no fine finish troweling labor required.

This is where section 09300.5 kicks in. Just prior to beginning the tile installation, the tile contractor shall pour a 1/2” thick layer of cementitious self-leveler product over the entire floor bringing it up to the finished floor elevation that is required. Any crowns, curls, humps, or other defects in the flatness of the concrete will be rectified during this process ensuring that a perfectly flat and level floor will be provided.

The specified floor covering product can then be installed in accordance with the appropriate specifications. The cost of installing the finished floor product should also be somewhat lower than normal considering that there will be no floor-prep work needed as it has already been provided for in #2 above.

There is no doubt that the total cost of this system will be slightly higher because self-levelers cost more to install than poured concrete, but that cost will be known up front on bid day. And let’s face it, costs of anything on bid day are usually much lower than add-on costs for extras later on.

Owners should also take into consideration that pouring large concrete slabs to a finished floor tolerance of 1/8” in ten feet is virtually impossible in the first place. There are simply too many variables during the curing and drying process to accomplish such perfection. Additional costs are a reality these days and this system will establish that total cost without confusion or cost over runs after the project is bid.

Specifications for the self-leveler product need not be excessive. A good quality self-leveler will produce a 28-day compressive strength of 4,000 psi. Depth per application ranges from 1” to 2” per pour. A primer is always recommended by each manufacturer.

I suggest that collaboration between the TCAA, the ASCC, and the NTCA will be needed to draft new language and get it distributed to the architectural community in order to get these important changes made. In my opinion this will be the total solution to the problem of how to get paid for performing floor-prep work. In the meantime the answer to that question is, “It can be difficult.”

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Tom Lynch is a 55-year veteran of the tile industry and one of the NTCA’s initial inductees to the “Recognized Industry Consultants” group. He can be reached at (336) 877-6951 or [email protected] or www.tomlynchconsultant.com. 

Does lack of 80% mortar coverage mean that a tile installation will fail? – Tech Talk – February 2018

By Tom D. Lynch, CSI

Not on your life! But you’d never know it by the way most professionals view this issue. The TCNA Handbook and ANSI A108 strongly recommend that 80% coverage should be attained for most installation scenarios, and rightfully so (exterior projects and showers recommend a minimum 95% coverage). The Handbook even goes so far as to offer explicit instructions as to how this can be obtained (thanks to Joe Tarver’s research years ago at the NTCA).

I agree wholeheartedly that the 80% goal should be reached on every tile installation; but I disagree that if it is not attained it will doom an installation to failure. I have seen too many installations that have been in for two years, three years and more that have never had the slightest inkling of failure until dramatic structural movement triggered lateral stress – most times as a crack in the concrete slab – that caused tile to dis-bond and shear loose. Then, if the coverage was something less than 80%, the tile contractor got blamed for the entire failure, or at least the vast majority of it. Never mind that the floor never failed for several years. Never mind that it is obvious that a crack in the concrete triggered the stress put on the mortar. It becomes the fault of the tile contractor because of the less-than-80%-coverage issue.

I disagree! I’m 100% on the side of the tile contractor here! Let me shed some needed light on this topic.

Let’s go back to the 1950s and ’60s when thin-set mortars were first being introduced to the market. ANSI was tasked with evaluating these new mortars that were beginning to replace full-blown mud-bed installations. ANSI A118.1 was developed, which included a porcelain tile shear strength rating of 150 psi. ANSI A118.4 came in at a porcelain shear of 200 psi. It was determined (and still is) that A118.4 has the desired mortar strength for installing porcelain tile. You with me so far?

Realizing that human beings are incapable of 100% perfection at all times, the Tile Council of America (now TCNA) and ANSI deemed it permissible to allow only 80% coverage for most installations. This is cool, but the one factor missing is that the ANSI testing is performed with 100% coverage on the test samples.

Oops! Now what?

If 100% coverage yields 200 psi, then it might be safe to assume that 80% coverage would yield only 160 psi. Make sense? Okay, so now let’s improve our installation mortar upwards to the newer A 118.15 mortars that achieve 400 psi shears with porcelain. 80% coverage with this mortar would yield a 320 psi shear strength which is exactly twice as strong as what A118.4 mortar achieves. This could also mean that only a 40% coverage rate with an A118.15 mortar would equal the required A118.4 rate of 160 psi at 80%.

What?? Am I suggesting that the rate of coverage be dropped to 40% minimums? Absolutely not! But what I am advocating is that if an installation has the tile edges and corners adequately supported and yet the coverage rate is something less than 80% it is NOT necessarily a cause for failure, and the tile contractor should be given the benefit of the doubt until the actual cause of the failure is discovered.

Up until now this 80% minimum coverage rate has been the death knell for tile contractors. It is unfair and needs to be stopped.

Here’s another point to consider. If the coverage on a particular failure was 80%-95% and a crack appeared in the slab causing the tile to shear loose, whose fault would it be? Obviously the concrete guy’s, right? So who can determine how much lateral stress the cracking of the concrete caused? 100psi, 200psi, 500psi, 1,000psi? It’s humanly impossible to determine, so let’s give the benefit of doubt to the tile contractor. Remember, when concrete cracks it’s generally like a mini explosion taking place – sudden and violent. It is never a silent and gradual separation.

I would venture a guess that there are more un-failed and completely successful tile installations in this country with less than 80% mortar coverage than there are with it. As professionals, let’s concentrate on solving failures rather than copping out by simply calculating coverage issues that more times than not unfairly condemn the tile installers.

Tom Lynch is a 55-year veteran of the tile industry and one of the NTCA’s initial Recognized Industry Consultants inductees. He can be reached at (336) 877-6951, [email protected] or at www.tomlynchconsultant.com. 

Tech Talk – January 2018

The TCNA Handbook for Ceramic, Glass and Stone Tile Installation

By The CTEF Blog

This article is the first of three articles that examine, explore and explain the documents and publications essential to the health of our industry: The TCNA Handbook, the ANSI Standards and the NTCA Reference Manual.

If you spend time with anyone involved in the proper installation of ceramic tile, the TCNA Handbook for Ceramic, Glass, and Stone Tile Installation will be the focal point of the conversation. Why? Because this useful guide assists in clarifying and standardizing installation specifications for tile.

In addition to providing a selection of numbered installation “methods” for differentiating and easy reference, the Handbook includes various product selection guides for ceramic, glass, and stone tiles; guidelines for wet areas; field and installation requirements, and more.

Produced by the Tile Council of North America (TCNA), the TCNA Handbook for Ceramic, Glass, and Stone Tile Installation has been published on a continuous basis since 1963.

Here’s an overview:

First, what is the TCNA?

Tile Council of North America is a trade association representing manufacturers of ceramic tile, tile installation materials, tile equipment, raw materials, and other tile-related products. It was established in 1945 as the Tile Council of America (TCA). In 2003, it became TCNA reflecting how its membership has expanded to include all of North America.

Tile Council is recognized for its leadership role in facilitating the development of North American and international industry quality standards to benefit tile consumers.

Additionally, TCNA regularly conducts independent research and product testing, works with regulatory, trade, and other government agencies, offers professional training, and publishes industry-consensus guidelines and standards, economic reports, and promotional literature.

One of the highlights of the yearly Coverings show is hearing TCNA Executive Director Eric Astrachan review the state of the ceramic tile industry – from an economic perspective as well as from a creative and trend perspective in North America.

TCNA also strongly supports the mission of the Ceramic Tile Education Foundation.

What is the TCNA Handbook for Ceramic, Glass, and Stone Tile Installation?

The TCNA website describes the Handbook as follows:

“A guide to assist in clarifying and standardizing installation specifications for tile. Each installation recommendation, or method, requires a properly designed, constructed, and prepared substructure using materials and construction techniques that meet nationally recognized material and construction standards. Included are: product selection guides for ceramic, glass, and stone tiles; guidelines for wet areas; ISO mortar and grout specifications; information on substrate flatness requirements; information on grout joint sizes and patterns, and workmanship standards excerpted from ANSI installation standards.”

The TCNA Handbook provides installation methods from which to choose, based on the requirements of the installation or the types of applications in which they may be used.

For example, will the tile be installed inside or outside? In a wet area such as a shower or steam room? Or in a dry area such as an entry foyer? Each method includes a generic drawing that shows each component or material required as you can see in the image below, which addresses installing stone floor tile.

How is the Handbook organized?

The TCNA Handbook works hand-in-hand with the ANSI Specifications to provide tile installations that are proven to stand the test of time.

In addition to detailing tile installation methods for ceramic and glass tile and natural stone tile, the Handbook includes:

  • Product selection guides for ceramic tile, glass tile, natural stone tile, setting materials, grout, backer board, membrane, additional products and Green Building
  • Field and installation requirements (i.e., substrate requirements, lighting, mortar and mortar coverage, flatness and lippage, grout joint size and pattern considerations, finished tilework, accessibility and wet areas guidelines)
  • Floor tiling installation guide
  • Environmental exposure classifications
  • Using the TCNA Handbook for specification writing
  • Installer and contractor qualifications guide
  • EJ171 Movement Joint Guidelines for Ceramic, Glass and Stone
  • Appendices and method locators

Each tile installation method details:

  • Recommended uses
  • Service rating
  • Environmental exposure classifications
  • Typical weight of tile installation
  • Limitations
  • Membrane options
  • Requirements
  • Materials (including for Green/Sustainable design)
  • Preparation by other trades
  • Movement joint requirements
  • Installation specifications
  • Notes
The evolution of the TCNA Handbook

The Handbook is truly a living, breathing entity that evolves in lock-step with the tile industry. As new products get introduced – for example, new tile formats and new mortars and tools to support those formats – new installations methods quickly follow to ensure best practices.

As a result, the Handbook has increased in size. A press release detailing changes in the 2017 issue includes the following:

  • The new sections “Tile Layout Considerations” and “System Modularity” are geared more toward those involved in tile selection and design. As an example of the various revisions to Handbook existing language, (Astrachan) noted the further explanation this year of substrate flatness requirements, which (he) calls “essential but too-often ignored.”
  • A prime example is the new Handbook section to address the newer type of steel studs commonly referred to as “equivalent gauge” or “EQ” studs. The new Handbook language helps people understand the most important considerations for avoiding tile problems when these thinner studs are used. Stephanie Samulski, Handbook Committee Secretary and Technical Content Manager, noted that “the specific design criteria that are ultimately needed will likely get hashed out in ANS.”
  • Other noteworthy changes that 2017 Handbook users will see include significantly more information on how to avoid the undesirable effects of wall-wash lighting on tile installations, new “Visual Inspection of Tilework” and “Design Considerations When Specifying Tile” sections, significant changes to the EJ171 movement joint guidelines, and a new method for tiling an exterior deck or balcony over unoccupied space (tile and stone versions).
What makes the Handbook unique?

The Handbook comes to life each year thanks to the Handbook Committee that includes representatives from the entire tile industry and all those touched by the tile industry – backer board, mortar, grout, membrane, tile and more manufacturers, industry associations, standards groups, construction specification groups and regional groups. It’s a balanced assembly of stakeholder voters that comes together to prioritize and address topics of concern.

The TCNA Handbook Committee determines Handbook content through significant group discussion and consensus efforts, and through meetings in person biennially and more frequently in workgroups.

As Astrachan explained, “The Handbook is a vehicle for providing industry consensus, but it’s not a standard and therefore not set up like one, enabling the committee to provide information in non-mandatory language when needed. It’s a particularly useful means of addressing conflicting recommendations or specifications, as can easily occur when a producer or another trade makes a major shift in product or practice in a way that impacts tile installations.”

Proposals for changes, often referred to as “submissions,” are welcome from any individual or organization.

Would you like to become involved in the TCNA Handbook?

All Handbook meetings are open to non-members, who are encouraged to participate in the discussions. If you would like to become involved, you can find meeting dates and locations posted on TCNAtile.com.

Tech Talk – December 2017

Have you added tile edge protection to your installation project?

How often are you including tile edge protection in your tile assembly specifications? Although not required for all installations, edge protection absolutely provides better results.

By Scott Carothers,
CTEF Director of Certification
and Training

Ultimately, if you’re serious about delivering only high-quality installations of ceramic, porcelain and stone tile, you must have the hand-skills to put the entire tile assembly into place along with the knowledge of what products are available to finish the project successfully.

Thinking about protecting tile edges is a perfect example.

What is tile edge protection?

You wouldn’t be in this business if you didn’t have an appreciation for how perfectly ceramic and porcelain tile function as floor and wall finishes. Tile is beautiful, durable, and easily maintained.

It has an amazing performance record and inspires intense product innovation.

Critical to your well-earned reputation is ensuring that your tile installation will perform despite heavy traffic. Edge profiles do the following:

  • Protect tile edges from chipping,
  • Provide easy transitions between adjacent floor and wall surfaces.
  • Deliver a design element that is often ignored.
Specify each component of the tile assembly

On most commercial tile jobs, the specifications clearly call out each component of the tile assembly, but not always.

However, on many residential jobs, the various items necessary for a good job may be overlooked.

Whether the project is commercial or residential, the tile installer is the last person on the job who should provide his or her input and expertise so that the ceramic tile installation is pleasing to the eye and will stand the test of time.

Don’t skip the little details!

Unfortunately the ultimate success of the completed project sometimes gets lost in the rush to get it done yesterday or in the little details that sometimes fall through the cracks.

Whatever the reason, the edge profile moldings are sometimes not included in the job. And yet, as mentioned above, these profiles play two key roles:

To provide a pleasing transition to the adjacent floor finish

To protect the edge of the tile, which may be a factory edge or a cut

Lack of edge protection means chipped tile

As seen in the photo below, which was taken from a hotel breakfast area, the edge of the wood-look ceramic tile is significantly chipped after only a few years of service.

Without the metal profile to protect the edge of the tile, unsightly chipping can (and does) occur.

In this case, the combination of the housekeeper’s sweeper and the metal legged chairs has taken its toll on the tile.

Consider exacerbating conditions

As you may have noticed in the photo above, the low-pile commercial carpet is 1/8” of an inch below the edge of the tile. This factor would definitely exacerbate the problem.

This may be particularly challenging, because you may not know the carpet pile height when discussing and developing a mockup for the project. Unless you consider the various possibilities, you may overlook the right product needed to finish the project successfully.

The tile otherwise has served the area well and looks great, but the chipped tile along the edge makes the entire job look unsatisfactory and unacceptable.

The real problem here is that when consumers see problems of this type, they often decide not to use tile in their next project. Their rationale is simple. If tile looks and performs like this (as seen in the photo), they don’t want it and will pick something else, which means everyone in the tile industry loses the job.

Proactive input eliminates problems

A small amount of proactive input prior to the job beginning would have eliminated this problem.

Many times the installer is not consulted on the design end of the project. But in this case, the installer gets blamed for the ugly result when in reality, he or she had no part in the process. The really odd thing about this hotel upgrade project is that all of the other installed tile surfaces included edge profiles.

The point here is that, as an installer, you should speak up and make recommendations that will enhance the project outcome and be a long-lasting testimonial to the durability and beauty of properly installed ceramic tile.

Certification signals your commitment to details like tile edge protection

If you haven’t already, consider becoming a Certified Tile Installer (CTI). As a CTI, you set yourself apart from the crowd and know how to anticipate tile installation problems before they occur.

Do it right the first time and get paid accordingly. Visit https://www.ceramictilefoundation.org/tile-certification-overview-ctef for details.

TECH TIP TUESDAY: ASK MARK – 11/21/17

Contractor Member Question

Mark,

Is there a way to determine what a stain on the surface of a tile is? We run into this problem every once in awhile.  I currently have a job that has been complete for a few months and they have sent pictures claiming the spots are thinset, membrane or grout.  I do not believe they are any of those things. Is there a way to tell? Please advise.

Mark’s Response

A recognized tile consultant either owns, or has access to laboratory technology that can test deposits on the surface of tiles.
A list of NTCA’s recognized consultants can be found on the NTCA website at this link:  http://www.tile-assn.com/?page=recconsultants
Any of the consultants listed on this page should be able to assist you.
I hope this helps.
Mark Heinlein
Technical Training Director

Tech Tip Tuesday: Q & A With NTCA Training Director Mark Heinlein – 10/31/2017

Consumer Question:

Hello! I’m trying to find out if there is an industry standard for the conversion rate of m to kg for Porcelain tiles based on thickness and if so, where I would be able to find this information. Thank you in advance for your assistance.

Mark’s Response:

Thank you for contacting the National Tile Contractors Association.

The Tile Council of North America (TCNA) Handbook for Ceramic, Glass and Stone Tile Installation contains an Appendix (B) discussing “Estimated Weights for Floor Installations.”

This appendix provides a discussion of assumptions for dead load weights of ceramic and stone tile and related setting materials. The assumptions are given in terms of imperial / US Customary (pounds per square foot) measurement vice metric (kilograms per square meters).  Several tables giving the weight calculations for methods included in the handbook are provided in Appendix B.

If you do not own the TCNA Handbook, a copy can be purchased from the NTCA’s Online Store under the Industry Technical Manuals section at this link:  https://tile-assn.site-ym.com/store/default.aspx?

I hope this helps.

 

Mark Heinlein

NTCA Training Director

Tech Tip Tuesday: Q & A With NTCA Training Director Mark Heinlein – 10/24/2017

Member Question:

We are encountering issues with a wall tile installation. I am trying to find out what the wall assembly should consist of in regards to metal studs, horizontal reinforcement, etc.   Your response would be greatly appreciated.

Mark’s Response:

Thank you for contacting the National Tile Contractors Association.

Please refer to the Tile Council of North America (TCNA) Handbook Method W243-17 for the details and best practices for the wall installation you are dealing with.  This method requires metal studs to be well braced; 20 gauge (0.033”) or heavier; minimum depth 3-5/8” for commercial applications.  The gypsum board must meet ASTM C1396/C1396M with a minimum of 1/2” thickness for single layer applications and must be installed per GA-216.  Maximum allowable variation of the substrate (for the installation of 12”x12” tile) is to not exceed 1/4” in 10’ (feet) from the required plane with no more than 1/16” variation in 12” when measured from the high points in the surface.  Additionally, details for movement and expansion must be met as required by TCNA Handbook method EJ-171.

I have attached a photo of the section of the 2017 TCNA Handbook that discusses “Equivalent Gauge” Steel Framing in case that material has been used on this project.

In addition, the NTCA Reference Manual includes an excellent discussion of EQ Gauge steel framing.  It states, in part, that the wall framing should meet a deflection limit of L/360 for the rated load based on the properties of the stud alone.  It further states that it is the responsibility of the design professional and framing contractor to ensure that wall assemblies for tile and stone finishes are designed and assembled to meet performance requirements, and all manufacturers of EQ studs will have the technical data needed for design and confirmation of performance requirements.

I am glad to learn you will be joining the NTCA.  As a member, you will find many benefits including tremendous networking and educational opportunities with many likeminded tile industry professionals looking to improve their level of performance and education based on tile industry standards. Other benefits include receiving a copy of the TCNA Handbook and the NTCA Reference Manual each year with your membership renewal.  I look forward to discussing membership with you next week when you call back.  In the meantime, please visit www.tile-assn.com for more information.  You can view additional member benefits at this link:  http://www.tile-assn.com/?page=Membership  you can also join by clicking on the “Join Now” link found anywhere on our website.

I hope this helps!

Mark Heinlein

NTCA Training Director

Tech Tip Tuesday: Q & A With NTCA Training Director Mark Heinlein

Member Question:

I have a job where we installed a porcelain tile. It is 8” x 15” and the side walls are fine but the wet walls are not good.  The worst part is they have that system of lighting where it is shining down directly from above so it shows all discrepancies and shadows. Is there anything in the industry standards that allows for a tolerance for a little lippage?

Mark’s Response:

Thank you for contacting the National Tile Contractors Association.

The standard for lippage is found in ANSI A108.02 Section 4 (copy attached) and is echoed in the TCNA Handbook.  Generally speaking, 1/32” in addition to the allowable warpage of a tile manufactured in accordance with ANSI A137.1 is the allowable lippage for wall mount mosaics with a grout joint width of 1/16 – 1/8”.

I understand these strip mosaics can be difficult and time consuming to install.  You are correct that substrate flatness is the place to start to help ensure the installed lippage is within tolerance.

The NTCA Reference Manual has an excellent section describing Wash Wall Lighting and how to avoid problems that can be associated with it.  If you have your Reference Manual at hand, it will provide some good reading on this topic.

The 2017 TCNA Handbook contains a section on Visual Inspection of Finished Tilework.  I don’t have my book close at hand but it is in the first 30-40 pages.  It may help your situation that visual inspection of wall installations is performed at 36” from the tilework.  Please take a look at that section in the Handbook and see if it can work for you in this case.

Please let me know if I can help with any further questions you might have after you are able to review the documents I listed above.

I hope this helps!

Mark Heinlein

NTCA Training Director

Tech Tip Tuesday: Q & A With NTCA Training Director Mark Heinlein

Member Question:

I need installation guidance to install a ceramic or porcelain tile over a concrete slab/sidewalk. This will be outside of a church and it is currently a concrete floor and curb. What would you recommend we use at the edge and expansion joints?

Mark’s Response:

There is a lot to consider before tiling a project like this one.  Since you may not have yet received your 2017 TCNA Handbook, I have attached a couple of photos of two methods (F101 and F102) that may be most applicable to your installation.

F101 describes an on ground concrete substrate with proper drainage below the slab, bonded mortar bed, ceramic tile and optional waterproofing / crack isolation membrane.

F102 describes an on ground concrete substrate with proper drainage below the slab, cementitious bond coat and optional waterproofing / crack isolation membrane.

Both of these methods will require proper drainage beneath the slab and drainage for surface water runoff from the finished surface and further drainage into the landscaping.  If the slab abuts a permanent structure, you will want to be certain that the drainage is slope away from the structure – the general rule would be 1/4” vertical slope per 12” of horizontal run.  Besides methods F101 and F102, there may be other methods and materials that will help with system drainage if that is an issue.

Prior to proceeding you will need to determine if this is a well cured slab and whether it is dimensionally stable and free of cracks, films, curing compounds, sealers, etc. and whether it’s surface has been at least steel troweled with a fine broom finish suitable for mortar to bond to it.  The flatness requirements of 1/4” per 10’ must be met for application of an F101 Thick Mortar Bed or for F102 direct bonding of tiles less than 15” on one side.  For direct bonding of tiles with one side 15” or longer the slab must meet the 1/8” per 10’ flatness requirement before the tile (or membrane) is to be set.

You will see that both of these methods list a membrane as optional.  Inclusion of a membrane will help with waterproofing above the substrate and a degree of crack isolation from minor existing or future in-plane cracks.  If the slab is abutted to a structure, I suggest looking for a way to flash the membrane up the side of the structure, potentially beneath the siding (if any).  The “Membrane Options” section of the method lists the specific membrane requirements and also points to Handbook methods F125-Partial / F125 – Full for crack isolation.

Some membrane manufacturers state that their membranes will be able to span certain types of joints if installed per their instructions and as part of a full system warranty (use of one manufacturer’s mortar, grout, membrane, sealant, etc.).  Installation of a membrane will help with waterproofing, some system drainage, and to protect against efflorescence from the substrate.

The “Materials” section defines the specifications for the tile and setting materials to be used in this method.

You are correct that this installation will need Movement Accommodation Joints.  TCNA Handbook Method EJ-171 provides the details.  As a minimum, those joints should be placed around the perimeter and at every change in plane or where the tile meets a different material.  Expansion joints in the concrete slab must be honored upward through the finished surface of the tile.  Expansion, Isolation, Construction, Contraction and other joints must be addressed.  For an exterior installation, joints throughout the tile field are required every 8’ – 12’ depending on materials and environmental conditions.  Appropriate joint width must also be determined based on environmental conditions the installation is expected to be subject to.  Sealants complying with ASTM C920 with an appropriate designation for this type of installation will be required for the soft joints.  As this is a traffic area, a sealant with a shore A hardness rating of 25 or greater should be considered.  Conversely, a manufactured joint may be available to use.  As we discussed in our workshop, it is the responsibility of the design professional or engineer to determine the location / placement / width / construction of these joints.  Method EJ-171 provides details on constituting these joints – but is too much information for me to forward in this e-mail.

Since this is an exterior installation with some potential of freeze/thaw cycling, expect there to be some system / component degradation over time that may require routine maintenance.

You will want to finish and protect the exposed edges of the tile with a commercially rated, durable metal trim such as brass or stainless steel. Bullnose, or tiles that have been custom bullnosed for the project may also work well depending on the expected use and conditions.

I hope this helps point you in the right direction.  You should have your new 2017 TCNA Handbook soon so you can refer to these methods and all of the other great guidance it contains.

Mark Heinlein

NTCA Training Director

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